Ink-jet printers form images on media by controlled ejection of ink from a printhead. Ink is present within a particular firing chamber of the printhead prior to being ejected through a corresponding nozzle. However, dogging of an inkjet nozzle can occur if ink is allowed to dwell within a firing chamber for sufficient time to dry out. Additionally, dwell time can cause constituents in the ink to stratify or precipitate out of solution. Such dogging, stratification or precipitation can result in malformed images, improper color rendition, streaks or other artifacts on the printed media, and so on. The present teachings address the foregoing and related concerns.